MQA Again

Hi all - the pricing on high res audio made me again thinking about MQA. Interestingly enough MQA is more expensive than the same files in 24 bit, which would assume that there is a physical or a perceived (marketing) differentiation in sound. So that poses a couple of questions for me:

1. Is there some kind of "independent" research or strong opinion on the forum about the differentiation between MQA and 24 bit traditional high resolution audio - so the what is better question or how does it sound different question ?

2. Tidal is offering it nowadays - assuming it would be better, how would I be able to play it on my NDS or is that right now impossible ?

3. People who are using it on an ongoing base what are there experiences, a significant different or just a marketing thing.

Original Post

To add to the discussion I have copied below a review of the tone audio magazine, which I believe is not a totally independent resource...

 

I gave Meridian’s co-founder Bob Stuart a difficult time a little over two years ago as he first told me about MQA, making it clear that I wasn’t going to tell you, my readers to buy Kind of Blue, again, no matter how compelling the demo he was about to show me would be.

The demo was amazing, and you wouldn’t expect anything less from Bob Stuart, undoubtedly one of high end audio’s most clever guys. Though Stuart is a confessed digital guy, it’s incredible that his latest creation is so analog sounding. A number of early reports on MQA have been less than bombastic, but like so many incredible things, the magic is in the details – in this case the fine details.

What Mr. Stuart has developed is certainly a paradox. As someone raised on fine analog, hearing MQA for the first time comes across as brilliant, but not in a hit your head with a mallet way. Yet the more analog you have heard, the more easily you’ll appreciate what MQA brings to the table. Music rendered via MQA has an ease and smoothness that you would normally associate with the best analog record and tape playback, in terms of musicality, with the dynamic range and speed accuracy you’d expect from digital. Sound like the best of both worlds? Well, it is.

Though Stuart started development work at Meridian, MQA is a separate company. As he mentions, “We had to set it up this way. First, it’s now a full-time job. Second it’s a completely different type of activity and in MQA we genuinely firewall our licensee activities from each other and that includes Meridian”.

It’s important to keep in mind that MQA is not really a new format, per se. Stuart and his staff say that MQA captures subtle timing information that is lost in the digital encoding process by creating a digital footprint of the recording chain of the album being played. In essence, they eliminate the sonic fingerprint of the gear going from the microphone to the DAC. Those worried that the sonic choices made by the artist and engineer to get said sound will be lost, have no fear. As much or little of the recording chain as the artist and/or producer want to leave in the mix can remain. This is why these recordings are referred to a “Master Authenticated.” They are all signed off on by the artist, so you know this is the record that the artist and producer intended you to hear in the first place.

A Sooloos server full of MQA files, from the 2L label and Warner Music, makes it easy to compare MQA to non MQA files in a relevant way. Good as the recordings from the 2L label are, these are not albums like Chicago V, Roberta Flack & Donny Hathaway, or Harvest; records that I’ve been listening to for most of my life, and also are available in nearly every format you can think of. Yet with all these classics at my disposal, the shootout begins with Metallica’s black album. Notoriously squashed of life and dynamics, this rock staple comes alive via the MQA process. The beginning of “Wherever I May Roam” is now full of life; rather than being met by a giant wall of overly compressed guitar crunch, the MQA version uncloaks layer after layer of information, providing more listening enjoyment, and illuminating the amount of care made in the recording session. Metallica has never sounded better in my system.

Multiple comparisons to the existing standard and high resolution files I have of the Warner classics on file, via Meridian’s latest 818v3 Reference Audio Core, which acts as a MQA compatible DAC, preamplifier and control system and a pair of 7200SE active speakers prove enlightening. Stuart tells me that this pair of 7200s is very special, because it is the same pair of speakers that he dragged around the world, doing all of the MQA demos for various label heads, artists and producers… Yet, you don’t have to spend $16,000 on a DAC to enjoy MQA. A number of hardware partners are now available (check www.mqa.co.uk for the latest count) and Meridian’s $299 Explorer 2 DAC gives a highly convincing demonstration.

Moving the 818v3 from my home listening room to main listening room at TONEAudio proves equally illuminating, where a direct comparison between MQA and a few other very good DAC’s but to make the ultimate comparison; MQA and vinyl. Again, this is where MQA really shines. For all the vinyl lovers in the audience (myself included), constant comparison between the recent 45 rpm LP remasters of the Neil Young catalog and the tracks available on MQA are nearly a dead heat. Nearly all of my non audiophile friends with no predisposed agenda prefer the sound of the MQA files to even LP, yet the same comments are made by everyone with no audiophile language; MQA sounds more relaxing, more real, more like music. So Mr. Stuart has hit a home run.

Again, is it a night and day difference? Not necessarily. Listening to great 24/192 vs. MQA is like going from a 7 Series BMW or S Class Mercedes to a Bentley. High quality versus very high quality, yet the difference is still there and as Mr. Stuart is fond of saying, “once you hear it, you can’t un-hear it.”

However, I think the even bigger difference or improvement that MQA brings besides another level of refinement is the way it will bring higher resolution to everyone. The main problem with 24/192 files is the size of the data pipe required to facilitate it. An MQA stream is right around 1100kb/sec, actually a bit smaller than uncompressed CD resolution files. This will be tremendous for those of us wanting high res to go, streaming from Tidal and eventually others. Stuart was kind enough to let me stream some beta files on Tidal and the results are excellent.

And this is what I like most about MQA, you won’t have to buy Kind of Blue or any of your legacy audiophile pressings again to enjoy the benefit of MQA. That’s what makes this really cool. Those that do want to purchase these titles will be able to very soon, but linking MQA with Tidal makes it a lot more diplomatic and cost effective.

In addition, files encoded with MQA will still sound better, cleaner on your standard digital setup even if you don’t have a DAC capable of decoding MQA. For now, let’s call the difference about 20% in terms of revealing more music in a less imposing (i.e. digital artifacts, etc) way than a non-MQA file.

The biggest hope for MQA is that as recording studios around the world adopt MQA as a standard and invest in MQA encoding hardware, forgoing the need to send the files to Meridian for encoding as they do now, future generations of musicians work will sound much better; that’s a triumph for everyone. That’s why MQA.

And Kind of Blue sounds pretty awesome too. Touche, Mr. Stuart.

From the mixing console: A chat with 2L’s Morten Lindberg and Bob Stuart

Morten Lindberg of 2L Recordings in Norway, has created some of the world’s finest recordings before MQA was introduced, and he has been a very early adopter of Bob Stuart’s technology, taking things even further. Both of these gentlemen were kind enough to give me an hour of their time, right on the tail end of the Munich High End show to discuss their relationship and process.

TA:  Do you feel that thanks to MQA, music going forward is going to sound a lot better?

ML:  When you’re talking about a well-done setup to a perfectly done MQA setup, yes it is, but comparing to many people with a standard digital setup it will be huge. So many users have shitty playback. There are some major differences.

BS: It depends on what kind of listener you are. Some listen to MQA and say it’s very subtle, others say it’s extraordinary, listening to different aspects of the sound.

TA: For me, MQA was an a-ha moment, but I was listening to a lot of tracks that I’ve been listening to for years, so it was easy. I recently hosted about 40 people in my home to A-B MQA and all but one not only preferred the difference, but heard the same thing. The one who did not prefer MQA said it was “too smooth.” I keep noticing that smoothness, which reminds me more of analog, because of the long tonal gradation that MQA processed recordings possess.

BS:  Exactly, it’s a back to analog, closed loop system now. When you take out the “problems” of digital, you get sounding back to the original. Yet when you hear it on a cell phone with earbuds, MQA still sounds much better and that’s what’s exciting.

TA:  Because the bitstream of an MQA file is much smaller than that of a 24/192 file it’s going to be that much easier for everyone to enjoy high resolution audio?

BS:  Yes, it’s smaller than a CD stream and much smaller than a high res file.

ML: Two years ago I didn’t know anything about Bob or MQA, and this is what first attracted me to the format. I felt our original high res files sounded just fine, but this might make it easier to distribute our high resolution files in a smaller container without losing anything. That was actually the entrance to MQA, the “origami” part of the MQA file. I had to prepare sometimes 8 or 9 master file sets, tailoring dithering and filtering for each sample rate the customer might use, so now just using one file that would unfold and work with multiple end users really attracted me. Originally Bob and I were to sit and talk for an hour, but after our first meeting went seven hours, it still took a while to understand the total philosophy of how we could implement it into our work.

TA: Are you recording your new projects in MQA format? Does it add or subtract from your digital workflow?

ML:  We’ve been meeting regularly in our studio, listening to music, talking about audio and recordings, defining what are we searching for, other than just redistributing our files. There are not yet easily available production tools, so we’ve been figuring out how to work together. While in production, I send raw files to Bob, he does his processing and I get options back. I’m used to turning a knob or pulling a fader and having something happen. This is different. Me listening to the files not knowing what was done and describing what I’ve experienced has been very helpful and taken my level of hearing to a new level.

BS:  And we’ve developed a common language for all of this.

ML:  Remarkably, it’s not very technical; more about color and emotions. We aren’t talking about frequency spectrums that much!

TA: So for now, you’re not really working with an MQA encoder per se, you’re using your current workflow then sending it off to Bob to process.

ML:  Yes, but we are looking forward to a more efficient process very soon. What Bob and I are doing is fine tuning.

TA: So if I understand both of you correctly, MQA essentially removes the “digital fingerprint” of the recording chain.

BS:  That’s what we are trying to do, and soon Morten will have a full MQA setup in his studio, but this process has helped both of us tremendously.

ML: We’ve done quite a lot of projects together and our catalog goes back to 2002, and we’ve gone back to eliminate that “digital fingerprint” from all of our files.

BS: One of the best things about even a great encoder is that you can still improve it further.

ML: It’s really difficult to describe this process, as it isn’t always one process requiring one action. When we listened to my Mozart recording in its original shape from 2006, we’ve now made some major and many minor actions to get it where it is today. We tend to refer to digital as one curse word. A lot has happened since the 80s and 90s and what has evolved from converter to converter as our process has evolved.

BS: The magic here is that by taking out the sound of the converters, even this recording done ten years back is a great recording!

JD: Now having MQA, and as the tools keep changing, changes your process as well. Using this going forward, does it then change how you setup in the studio? Mic choices, mic placement.

ML:  Even though we don’t employ the MQA process when recording (Stuart chimes in “Not yet”) I would like to have MQA in my listening at the venue, it’s embedded in my brain so I know what slight differences I can change when recording.

JD: The parallel to photography stays in my mind, it seems to be a lot like pre visualizing what the end result will be.

ML:  Yes, definitely

BS: We find that Morten’s recordings with two mics, are the cleanest ones we’ve encountered. With other multitrack digital recording you have more blurring because more mic feeds are being processed. With more channels, there’s more blurring, hence the need to turn it up louder. You have to use brighter colors. Once you clean the picture, you don’t have to make the colors as bright to be seen. You can’t expect to make a great recording with 200 microphones.

ML: But they keep trying! This really goes to my heart. Most engineers are more concerned with abuse afterward from the producer or artist. I’m sorry if I seem harsh.

TA: Morten, with this being said, is there any chance of you working outside the current genres of music you now work in?

ML: Of course. It doesn’t matter what kind of music it is, it comes down to my craft and my approach to recording music. Part of the production is finding the right venue, the right room for any given type of music. Instruments balancing in a natural way is a big part of what I do. And this would be more than you might think.

TA: I agree with you gentlemen on all counts. Morten you offer your digital test bench so people can actually hear not only the difference between file formats, and resolution. How long has this been going on and whose idea was this?

ML:  It was my idea from the moment we started to distribute our original masters. About 2008 and it’s a simple web server, delivering about a terabyte a week of different samples.

TA: So back to our original topic somewhat; MQA is helping to simplify the process of downloading high resolution digital music files.

BS: Yes.

ML: Our job is to deliver the best sounding original recording we can in the final format that the customer wants to hear.

Conclusion

The digital process continues to advance, and both Bob Stuart and Morten Lindberg are major players on both sides of the console. With guys this passionate working for us, music delivery will continue to evolve and improve. You may hear a number of arguments on the internet or at the pub, but in the end, we at TONEAudio feel MQA is a huge step forward in digital music fidelity and delivery. We urge you to experience it at your convenience.

And another interesting viewpoint on the same matter...from open source...

Why the proprietary MQA music encoding system is better than DRM, but still not good

Why the proprietary MQA music encoding system is better than DRM, but still not good
Image by : 

Opensource.com. CC BY-SA 4.0

In June 2016, I wrote about the MQA proprietary closed-source music encoding system and shared my thoughts on why I felt the system is not a good thing. Since then, I've been reading more about MQA so this month I'll share additional thoughts.

First, MQA (Master Quality Authenticated) is made up of a whole bunch of moving parts, many of which seem interesting for various reasons. The description on Wikipedia refers to MQA as an "audio codec" (codec is short for coder-decoder). An important technical part of the MQA codec is that it provides a form of audio signals compression, so that those signals take up less space. In principle, this is similar to the advantage FLAC brings: FLAC—the Free Lossless Audio Codec—uses a non-destructive reversible compression algorithm to tightly pack PCM format audio signals for storage or transmission, and unpack them for playback. FLAC files are typically about 50% of the size of non-compressed PCM, which we most often see as WAV files on our computers.

Compression of music files is important for several reasons. First, music files can take up a lot of space. On my laptop, with its 480 GB SSD, my Music directory consumes 190 GB, storing 5,662 songs for an average of just more than 33 MB per song. Clearly I could not put my entire library on my SSD in uncompressed format; FLAC makes it fit. Second, by using FLAC, I use half the bandwidth that uncompressed data would need. This is good for me, and it's also good for the online stores from which I buy music. This is especially true for clients of streaming services—less bandwidth equals lower cost and fewer "buffering" messages.

At this point, you're probably wondering: So if we already have an audio codec, FLAC, that compresses files down to 50% of their original size and decompresses them for playback, why do we need MQA? And those of you who know about Ogg Vorbis or MP3 are aware that, provided we can tolerate some loss of audio quality, we can improve considerably on that 50%.

As can sometimes be the case, such an apparently simple question uncovers a number of answers.

Types of listeners

First, let's look at this from a listener's perspective—or more accurately, what the music industry thinks of its listeners. An article in Stereophile describes new "high resolution listening stations" to be set up in Best Buy stores and some market research apparently carried out by a consortium of audio companies called the Digital Entertainment Group (DEG). In the summary of the study, they identify four types of listeners:

  • music lifestyle group (44% of listeners), for whom music serves mainly to accompany other activities;
  • emotional music lovers (32% of listeners), who "are totally committed emotionally to music" and are "streaming customers" and "the future of hi-res music";
  • high-tech audiophiles (15% of listeners);
  • and the disinterested customers (9% of listeners), who "don't care about music at all."

From this breakdown, we can probably infer that the music lifestyle group and the disinterested customers are satisfied with cheap and cheerful MP3 format music, whether streamed or purchased. We also can probably infer that those high-tech audiophile types are looking to wring the last few bits out of their digital music, when they can pull themselves away from their collections of LPs.

The point of the market research, though, is that the emotional music lovers could also be enticed into the high-fidelity camp, and in any case, their interest in streaming indicates that a high-quality streaming option should be provided, with accompanying gear to consume it.

And, so…? How does this create space for the new MQA codec?

Higher than CD resolution

Primarily, MQA attempts to address the "higher than CD resolution" in an efficient way. In my music library, I have two copies—from different sources—of the Rolling Stones' song "Gimme Shelter". One is ripped from a "best of" CD bought a dozen years ago, and is therefore 16 bit/44.1 kHz "CD quality" coded into a FLAC file that takes up 30.7 MB. The other, from a high-resolution download of Let it Bleed (what a great album), bought since then, is 24 bit/88.2 kHz "better than CD quality" and takes up 94.9 MB. Interestingly enough, simple algebra predicts that going from 16 to 24 bits and from 44.1 kHz to 88.2 kHz should produce a file size of 92.1 MB, not far from the actual file.

MQA attempts to approach the quality of the higher resolution file while using a compression technique that is closer to the CD end of things. Its compression technique is described in many places around the Internet, but an article in Stereophile is quite clear on many aspects of MQA. In short, the process recognizes that the inherent noise floor of the music recording does not permit the full use of the 24 bits available and therefore the noise—the lower order 7 or 8 bits—can be "reused" to store the low-level high-frequency components. Thus, the final music file looks more like a 24 bit/44.1 kHz file (or 24/48 file if the source was 96 kHz rather than 88.2 kHz). If we considered my Stones example above, we might expect an MQA version to take up 46 MB or so (algebra again). Thus MQA recognizes that most music is approximately no better than 16-18 bits of music, so that a 24-bit word length "wastes" 6-8 bits.

The problem with MQA

Ok, now we understand how the compression thing in MQA works, more or less, and what it produces. So why do I think MQA is not a good thing?

MQA is patented and the patent owner licenses the use of its patent to the recording and reproduction side of the chain. That is, unlike FLAC, MQA provides a mechanism to control the recording studios, distribution channels, and listeners. The owners of MQA make it clear that we can listen to MQA-encoded files on hardware that does not provide an MQA decoder, but what we are listening to in that case is the more or less CD-quality portion of the music stream that is not hidden in the "new noise."

An article on Computer Audiophile explains that result in more detail, and goes on to show how similar compression levels can be obtained in pure FLAC by throwing away the parts of the original data that contain only noise.

Because MQA is patented, commercial, and proprietary, MQA plugins for Linux audio players are unlikely, although perhaps a binary-only non-free plugin may eventually come along for sale or free download. Thus, Linux users who want to listen to full-quality MQA files are forced to purchase an MQA-compatible digital-analog converter.

MQA is not quite as exclusionary as the DRM used by some music distributors. MQA files can be played on any equipment, but what will be heard on equipment that does not contain a licensed MQA decoder is essentially the CD-quality component with a bunch of low-level, high-frequency noise added. And, oh yes, those files will be approximately 50% bigger—in other words, the cost of downloading or streaming is borne by all, whether they have an MQA decoder or not. I really dislike this aspect of MQA. The MQA owners claim that MQA encoding actually improves the quality of the music even when it is played back on non-MQA-capable devices, so perhaps there is benefit to all-in exchange for the big files and the proprietary lock-in.

Not all manufacturers are in favor of MQA, either. Both Schiit Audio and Benchmark Media Systems are giving it a pass for both "open" and "engineering" reasons. The people at Schiit also note that MQA, in creating yet another newer/better format, creates yet another opportunity for the music industry to sell the same music all over again.

And so, having had for several years the ability to acquire music in open formats that do not interfere with our ability to select software or equipment to play them back, we are being invited to return to the old days where the music industry controls our playback devices. I don't think this is a good thing. If you agree with me, please join me in saying "no" to MQA.

 

In answer to the question of MQA vs the same high res source in straight .flac format without going through a lossy compression and decompression process that is MQA, then I would expect the non-lossy process to be closer to the original sound recorded, and therefore better., though I haven't heard MQA myself, and I suspect it would depend on the resolution and response of the system and of the listener's ears/brain.

More to the point, I don't see the benefit of MQA to the listener,  except where online streaming with a borderline internet connection that can't manage the data speed of the hi res file but can manage half (or whatever it is) that rate. To me, far better to just download the hi res file and play it. There is a benefit to the online streaming supplier, because it halves their bandwidth, for which they pay - so the MQA files should be offered at a significantly cheaper rate: and that would be fair if indeed the sound quality suffers as a result of the lossy process as has been saidin previous discussions on this forum.

If you start with a 16/44.1 file and you process it with MP3, information is lost.
If you start with a 24/192 (or 24/96 or 24/88.2) file and you process it with MQA, information is lost.

If you play an MQA file and play it on a 16/44.1 decoder, some of the 16/44.1 information is lost, as some of the HF information is scrambled to accommodate the information used to increase the resolution below 16bits.  This scrambled information cannot be decoded correctly by a 16/44.1 decoder, so is presented to the listener in scrambled form (and your brain can't decode it either).

 

MQA played back on an MQA decoder has less information than a 24/192 PCM stream.
24/192 FLAC played back on an 24/192 decoder has the same information as a 24/192 PCM stream.

MQA played back on a 16/44.1 (or 24/192) decoder has less information than a 16/44.1 PCM stream.
16/44.1 FLAC played back on a 16/44.1 (or 24/192) decoder has the same information as a 16/44.1 PCM stream.

Dozey posted:

The way to get MQA from Tidal playing through the NDS is to go to the Tidal website and favourite the MQA albums. Then when you look at your favourite albums using the Naim app and the NDS you will see them in the list.

 

But as, I believe, NDS does not decode MQA, playing direct through NDS will be playing the MQA compressed  version without decoding, so not even reaping the claimed benefits of MQA, regardless of whether those claims are justified!

 

Innocent Bystander posted:
Dozey posted:

The way to get MQA from Tidal playing through the NDS is to go to the Tidal website and favourite the MQA albums. Then when you look at your favourite albums using the Naim app and the NDS you will see them in the list.

 

But as, I believe, NDS does not decode MQA, playing direct through NDS will be playing the MQA compressed  version without decoding, so not even reaping the claimed benefits of MQA, regardless of whether those claims are justified!

 

I tried that on a few albums on my NDX just to see what the fuss was all about, and the SQ was pretty similar to regular 16/44 streamed Tidal, i.e. not as good as a CD rip.

Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

In the case of MQA not being decoded when it is played by NDS, unless Naim has done something unannounced with a recent firmware update it is fact, not scepticism - so what you are playing is the encoded compressed MQA file, not the restored in all MQA's claimed glory file.

However, IIRC it has been observed that some people perceive the audible artefacts as improvements, in the same way as some people perceive the effect of RF noise floor modulation in DACs giving an apparently 'brighter' sound as being better, though both are degradations of the original signal as recorded and mastered. Of course, as with all music reproduction, if you like what you hear then it is good, even if others dont or if it is not high fidelity in the strict meaning of the term.

Huge posted:

If you start with a 16/44.1 file and you process it with MP3, information is lost.
If you start with a 24/192 (or 24/96 or 24/88.2) file and you process it with MQA, information is lost.

If you play an MQA file and play it on a 16/44.1 decoder, some of the 16/44.1 information is lost, as some of the HF information is scrambled to accommodate the information used to increase the resolution below 16bits.  This scrambled information cannot be decoded correctly by a 16/44.1 decoder, so is presented to the listener in scrambled form (and your brain can't decode it either).

 

MQA played back on an MQA decoder has less information than a 24/192 PCM stream.
24/192 FLAC played back on an 24/192 decoder has the same information as a 24/192 PCM stream.

MQA played back on a 16/44.1 (or 24/192) decoder has less information than a 16/44.1 PCM stream.
16/44.1 FLAC played back on a 16/44.1 (or 24/192) decoder has the same information as a 16/44.1 PCM stream.

So if I take it, you are saying that it will never be better in a like for like, thanks for your viewpoint.....

The op asked if the nds can play mqa files The answer is yes it can and I explained how. It is correct that it cannot decode the way an mqa dac can.

The scepticism I was referring to is whether it sounds any better than regular 16/44 tidal. I suspect opinions will vary. However I would not discount it on theoretical grounds when it is so easy to listen for yourself, and when psychoacoustics can vary from person to person

Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

Note that I didn't say that it couldn't sound better in the perception of a given person using a particular set of equipment; but that there was a loss of information and that the 16/44.1 signal wasn't as good as CD quality.  Those statements are derived from information theory and are entirely defensible.

If it sounds better to you than the equivalent PCM stream, then the artefacts in the MQA stream are either covering up, or in some way compensating for, a deficiency in your playback equipment or your perception.

Scepticism simply doesn't enter into that side of things.

Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

This is my general approach. Stranger things have happened.

When faced with a plethora of experiments to try and only a finite time to try them in, you start to filter and sort. It's here that MQA falls down for me. The reasons given for it's existence just aren't credible enough. Who needs to save disk space? It's never been cheaper. Who needs to compress and uncompress something in order to hear it when you can just play an uncompressed version of it? Less potential for errors and artefacts. 

Compression is a nice fudge term. It implies a squeeze, rather like liquefying a gas. But it's actually removing data from a file and then interpolating it on playback. That's never good. I suppose that for limited bandwidth this might be an improved delivery system. Waste of an NDS though. Waste of an ND5 come to that. 

I won't knock it until I've tried it but if I never try it I will remain sceptical. Bit circular but that's life.

Scepticism is saying it can't be any better without trying it. Note I have nowhere said that I think it is any better.

TBH I don't hear much difference. I do like the option of listening to both and trying to work out what the differences (if any) are.

16 bit PCM: 15 bits of valid data + 1 bit of noise

MQA via a non MQA decoder somewhere between 10 and 13 bits of valid data and 3 to 6 bits of uninterpretable compressed data that appear as pseudo random data and have the approximate effect of noise.

MQA has less valid data available...  Where's the scepticism?

Hi Huge, although I agree with the thrust of your comments, I don't think it's fair or accurate stating a 16 bit PCM signal is usually 15 bit data plus 1 bit noise , is it not more typically 16 bit data with a random distribution function of one sort or another of  least significant bit data, typically depending on frequency content effectively XOR'd with the 16 bit sample data? And this depending on the noise frequency shaping  of the dither can give a perception of increased dynamic range beyond 16 bits too

Statistically it's part data part noise (but truly understanding how that work requires a considerable mathematical understanding).

Any random distribution function not correlated to the data is, by definition, noise.

I'm still not convinced that the human ear/brain combination functions like a FFT (or MEM) frequency analyser to reduce the perceived noise below 16 bits.

 

Timmo1341 posted:

There are many things in life that some people do, consume, use, listen to.....etc. The fact they do so and purport to enjoy does not mean I have to indulge in same activity to justify being critical, dubious or sceptical.

your purpose is too general to have inner meaning.

Keler Pierre posted:
Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

agree 100%.  a lot of people like to show their technical knowledge but have even not tested with their ears.....what a waste of time....

If it simply can't sound as good, why would one want to bother trying it?

Actually, having asked the question there is an answer, though one perhaps many people are likely not to want to explore, namely to discover whether they really prefer unadulterated perfect reproduction or something knowingly compromised...

Innocent Bystander posted:
Keler Pierre posted:
Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

agree 100%.  a lot of people like to show their technical knowledge but have even not tested with their ears.....what a waste of time....

If it simply can't sound as good, why would one want to bother trying it?

Actually, having asked the question there is an answer, though one perhaps many people are likely not to want to explore, namely to discover whether they really prefer unadulterated perfect reproduction or something knowingly compromised...

the answer in in your ears. A lot of reviews by audio specialists were made, pointing that mqa offers sound improvement. They tested it and compared the sound of mqa/ non mqa files on the sound quality side. I am more confident in reviews of absolute sound, hifi critic and stereophile than speculations of some members who are trying to play specialists.

Keler Pierre posted:
Innocent Bystander posted:
Keler Pierre posted:
Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

agree 100%.  a lot of people like to show their technical knowledge but have even not tested with their ears.....what a waste of time....

If it simply can't sound as good, why would one want to bother trying it?

Actually, having asked the question there is an answer, though one perhaps many people are likely not to want to explore, namely to discover whether they really prefer unadulterated perfect reproduction or something knowingly compromised...

the answer in in your ears. A lot of reviews by audio specialists were made, pointing that mqa offers sound improvement. They tested it and compared the sound of mqa/ non mqa files on the sound quality side. I am more confident in reviews of absolute sound, hifi critic and stereophile than speculations of some members who are trying to play specialists.

But I assume the reviews to which you refer relate to the sound when decoded ("unfolded") (and maybe fully in an MQA DAC not partially as can be done in rendering software?), as opposed to playing the MQA file through player like NDS that doesn't decode it, which is the subject of my comment. 

Huge posted:

Statistically it's part data part noise (but truly understanding how that work requires a considerable mathematical understanding).

Any random distribution function not correlated to the data is, by definition, noise.

I'm still not convinced that the human ear/brain combination functions like a FFT (or MEM) frequency analyser to reduce the perceived noise below 16 bits.

 

Absolutely it's parts data part noise which was my point ... so I think we are on the same page there as of course a random distribution function can't be correlated to a signal. Didn't understand your point about ear/brain functioning as a FFT analyser... all the information I have seen especially from the AES is that it doesn't, which is why why our timing sensitivity in our hearing is not directly related to the frequency response of our hearing. However our hearing frequency/dynamic range perception is non linear... so we perceive more dynamic range in some frequencies that others.. and this phenomenon is used with some dither noise shaping as well as with noise shaping with DSD for example.

Innocent Bystander posted:
Keler Pierre posted:
Innocent Bystander posted:
Keler Pierre posted:
Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

agree 100%.  a lot of people like to show their technical knowledge but have even not tested with their ears.....what a waste of time....

If it simply can't sound as good, why would one want to bother trying it?

Actually, having asked the question there is an answer, though one perhaps many people are likely not to want to explore, namely to discover whether they really prefer unadulterated perfect reproduction or something knowingly compromised...

the answer in in your ears. A lot of reviews by audio specialists were made, pointing that mqa offers sound improvement. They tested it and compared the sound of mqa/ non mqa files on the sound quality side. I am more confident in reviews of absolute sound, hifi critic and stereophile than speculations of some members who are trying to play specialists.

But I assume the reviews to which you refer relate to the sound when decoded ("unfolded") (and maybe fully in an MQA DAC not partially as can be done in rendering software?), as opposed to playing the MQA file through player like NDS that doesn't decode it, which is the subject of my comment. 

As for fully decoded MQA, as it is a lossy compression process the restored version will not be identical to the original hi res - but whether any individual person can discern a difference when playing it depends on their ears/brain and the resolution of their system, and indeed, as I noted, some people if they can hear a difference might prefer the sound of the altered version.

If course if anyone were to compare the sound of a high res file such as 24/196 compressed with MQA and then restored, against a CD quality 16/44, that is quite a different matter (and completely irrelevant if the 16/44 and 24/96 are from different masterings as is can happen).

My question is simply why bother with MQA, why not simply download the hi res file and enjoy it in all its maximum potential glory?

Meanwhile, of course, there is always the theoretical argument that it is not possible to hear better than can be encoded to red book, but that is quite another matter....

IB, the problem I have with MQA is the creation by its process of the non harmonic aliases caused by the encoding/ decoding decimation process... if you like the when the high frequency elements are 'unfolded' the 'creases' are left in the signal... from my limited understanding of MQA it appears careful filter response curves are required to minimise this and also statistically it appears that MQA relies on the fact that this added digital distortion most will not find objectionable.... and perhaps the marketeers are working on the idea that some prefer the sound of this added distortion to position it as a selling point.. and fair play to them if some do prefer this..

However to your question why use MQA, well my understanding is that it can provide an aporoximation to higher resolution audio formats using more efficient data transmission... and that is on balance probably a good thing.. useful for current mobile coms and shared wifi spaces... it's also fair to say in current hidef  lossless audio transmission, even with FLAC, the data transmission is extremely inefficient.... there is usually much data that is encoded that is not relevant to the information contained.. ultrasonic noise for example...

Bert Schurink posted:

Hi all - the pricing on high res audio made me again thinking about MQA. Interestingly enough MQA is more expensive than the same files in 24 bit, which would assume that there is a physical or a perceived (marketing) differentiation in sound. So that poses a couple of questions for me:

1. Is there some kind of "independent" research or strong opinion on the forum about the differentiation between MQA and 24 bit traditional high resolution audio - so the what is better question or how does it sound different question ?

2. Tidal is offering it nowadays - assuming it would be better, how would I be able to play it on my NDS or is that right now impossible ?

3. People who are using it on an ongoing base what are there experiences, a significant different or just a marketing thing.

I think their can can be too much oversampling with 24 Bit reading.. Files can sound thin and horrible. I Think Naim amps are that sensitive that sometimes when I listen to HD files they sound worse than the original recordings. To my ears HD sounds forward and flatish in sound.. But then again I prefer vinyl and am happy listening to Spotify on my computer through a DAC..Also I am getting older so hearing may not be able to decode the benefits of HD etc.

Simon-in-Suffolk posted:
Huge posted:

Statistically it's part data part noise (but truly understanding how that work requires a considerable mathematical understanding).

Any random distribution function not correlated to the data is, by definition, noise.

I'm still not convinced that the human ear/brain combination functions like a FFT (or MEM) frequency analyser to reduce the perceived noise below 16 bits.

 

Absolutely it's parts data part noise which was my point ... so I think we are on the same page there as of course a random distribution function can't be correlated to a signal. Didn't understand your point about ear/brain functioning as a FFT analyser... all the information I have seen especially from the AES is that it doesn't, which is why why our timing sensitivity in our hearing is not directly related to the frequency response of our hearing. However our hearing frequency/dynamic range perception is non linear... so we perceive more dynamic range in some frequencies that others.. and this phenomenon is used with some dither noise shaping as well as with noise shaping with DSD for example.

Simon my point about the ear brain combination was to do with the perception of noise - that is the brain distinguishes noise as an identifiable signal and separates it from other signals (in just the same way as you can distinguish the different timbres of different instruments).  However the brain is also programmed to tune out the significance of the (uncorrelated) noise signal after extracting it from the perceptive field.  This is for instance used to detect small sounds in the presence of louder wind noise.  Unlike an FFT, the brain does this by treating the whole of the noise together as separate, identifiable  signal and then ignoring it, rather than mathematically reducing it by deconvolving the sine/cosine components of each frequency step.

The problem with undithered quantisation noise is that it's correlated to the signal and thus two things are likely occur
Firstly part of the correlated signal distorts the perception of all the wanted signals, confusing their purity and intermixing them (i.e. reducing your ability to distinguish the different timbres of different instruments, and listening to some dithered and undithered samples I seem to have experienced this).
Secondly will interferes with the way the brain does the post processing to reduce it's significance as the noise is partly related to the signal it wants to keep, thus increasing the processing demand required in the brain needs to successfully identify it clearly enough to ignore it, and hence reducing the efficiency.

My understanding of the perceptual use of dither is to break up the correlated quantization noise pattern to a sufficient degree that the brain processes it as a separate, entirely uncorrelated noise signal.  The amount of dither needed to do this will be very strongly correlated to the amount and statistical distribution of dither noise that will shift the noise to the ultrasonic region as shown in an FFT; as this will minimise the additional noise that can be perceived in the audio band.  However, given that the brain processes uncorrelated noise as a separate signal, I don't see how the perceived noise can be reduced below -16 bits.

In fact I'd expect the minimum to be the energy equivalent of -15.5 bits but I think the difference between that and -16bits is too small to be distinguished experimentally.  It may be possible to design an experiment that would detect if the brain can reduce the perceived level to -17 bits or lower based on σ=3dB and p=2σ, but that would be pushing it to the limit of experimental confidence.

I didn't realise that there was a second superimposed noise shaping used to shift the noise based on the ISO revision of the Fletcher-Munson contours - presumably with compensation for cochlear compression as the energy is pushed into higher density bands, that gets quite mind boggling!

Innocent Bystander posted:
Keler Pierre posted:
Innocent Bystander posted:
Keler Pierre posted:
Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

agree 100%.  a lot of people like to show their technical knowledge but have even not tested with their ears.....what a waste of time....

If it simply can't sound as good, why would one want to bother trying it?

Actually, having asked the question there is an answer, though one perhaps many people are likely not to want to explore, namely to discover whether they really prefer unadulterated perfect reproduction or something knowingly compromised...

the answer in in your ears. A lot of reviews by audio specialists were made, pointing that mqa offers sound improvement. They tested it and compared the sound of mqa/ non mqa files on the sound quality side. I am more confident in reviews of absolute sound, hifi critic and stereophile than speculations of some members who are trying to play specialists.

But I assume the reviews to which you refer relate to the sound when decoded ("unfolded") (and maybe fully in an MQA DAC not partially as can be done in rendering software?), as opposed to playing the MQA file through player like NDS that doesn't decode it, which is the subject of my comment. 

yes, with fully mqa dac. I was not commenting specifically your comment , more some other responses...

Innocent Bystander posted:
Innocent Bystander posted:
Keler Pierre posted:
Innocent Bystander posted:
Keler Pierre posted:
Dozey posted:

Well, I suggest you try it for yourself if you are sceptical.

agree 100%.  a lot of people like to show their technical knowledge but have even not tested with their ears.....what a waste of time....

If it simply can't sound as good, why would one want to bother trying it?

Actually, having asked the question there is an answer, though one perhaps many people are likely not to want to explore, namely to discover whether they really prefer unadulterated perfect reproduction or something knowingly compromised...

the answer in in your ears. A lot of reviews by audio specialists were made, pointing that mqa offers sound improvement. They tested it and compared the sound of mqa/ non mqa files on the sound quality side. I am more confident in reviews of absolute sound, hifi critic and stereophile than speculations of some members who are trying to play specialists.

But I assume the reviews to which you refer relate to the sound when decoded ("unfolded") (and maybe fully in an MQA DAC not partially as can be done in rendering software?), as opposed to playing the MQA file through player like NDS that doesn't decode it, which is the subject of my comment. 

As for fully decoded MQA, as it is a lossy compression process the restored version will not be identical to the original hi res - but whether any individual person can discern a difference when playing it depends on their ears/brain and the resolution of their system, and indeed, as I noted, some people if they can hear a difference might prefer the sound of the altered version.

If course if anyone were to compare the sound of a high res file such as 24/196 compressed with MQA and then restored, against a CD quality 16/44, that is quite a different matter (and completely irrelevant if the 16/44 and 24/96 are from different masterings as is can happen).

My question is simply why bother with MQA, why not simply download the hi res file and enjoy it in all its maximum potential glory?

Meanwhile, of course, there is always the theoretical argument that it is not possible to hear better than can be encoded to red book, but that is quite another matter....

the advantage of mqa is for streaming from tidal. As for streaming real high rez which we have downloaded, it is better than mqa as you said.

 

 

 

 

 

It would be a good thing that in the future we will be able to stream full high rez....no need to buy, download, edit.....For now, if nds could have mqa, it would be too a good thing i think.

ndx202- posted:
Bert Schurink posted:

Hi all - the pricing on high res audio made me again thinking about MQA. Interestingly enough MQA is more expensive than the same files in 24 bit, which would assume that there is a physical or a perceived (marketing) differentiation in sound. So that poses a couple of questions for me:

1. Is there some kind of "independent" research or strong opinion on the forum about the differentiation between MQA and 24 bit traditional high resolution audio - so the what is better question or how does it sound different question ?

2. Tidal is offering it nowadays - assuming it would be better, how would I be able to play it on my NDS or is that right now impossible ?

3. People who are using it on an ongoing base what are there experiences, a significant different or just a marketing thing.

I think their can can be too much oversampling with 24 Bit reading.. Files can sound thin and horrible. I Think Naim amps are that sensitive that sometimes when I listen to HD files they sound worse than the original recordings. To my ears HD sounds forward and flatish in sound.. But then again I prefer vinyl and am happy listening to Spotify on my computer through a DAC..Also I am getting older so hearing may not be able to decode the benefits of HD etc.

well done high rez sound more natural, extended and dynamic, like vinyl. But there are also a lot of high rez which sound edgy and little harsch.   Personally i buy only modern recordings on high rez format.  For music originally on vinyl, i prefer like you vinyls on my turntable.

Hi Huge, yes a digitised signal where there is less than ±.5 LSB of variation for several consecutive samples can get stuck at a sampled quantisation value  and become audible especially at lower bit depths, so noise distributed with a standard deviation of 2/3  LSB  is often added to remove this quantisation  'stickiness', and remove these audible artefacts in the digitised signal.... but interestingly peak to peak noise value of a random signal is approx 6 times  the value of its standard deviation. .. which equals approx 3 to 4 LSB peak to peak noise added to the digitised signal.... but even more interestingly adding this distributed noise allows us to extract more information from this digitised signal stream.

Simon

All the discussion about the technical merits (or not) and the musical merits (or not) are really rather trivial compared to the main points:

- it is proprietary and therefore will only play to the full extent on licenced equipment. You will be buying music that won't play to its fullest extent on any device. Why buy into such a restriction?

- it is lossy. You can buy the lossless version, so why bother?

- it was invented to address the issue of streaming large data files. Given that most homes now stream movies with multiple 24 bit channels, the restriction it was intended to address is no longer there

- artists, recording studios, playback device manufacturers,labels and distributors all have to pay a licence to use the system. This is adding additional costs into the industry yet there seems to be no benefit in doing so. Music costs will increase for no listener benefit. More expensive music encourages more piracy, it does not address piracy.

- a little light comes on to prove you are listening to MQA which is supposed to be an indicator of quality. However, there has been debate in the industry about the authenticity of some of the souce material and the accuracy of the information about the equipment used to create the master. This is important in a system that claims to correct for errors in the original recording equipment.

- an authenticity system also allows for the authenticity to be re-interpreted in the future to restrict access to content paid for but not continuously licenced. Think about the impications of a change to licencing terms in the future.

All of this is far more important that 'does it sound any good?'

sunbeamgls posted:

All the discussion about the technical merits (or not) and the musical merits (or not) are really rather trivial compared to the main points:

- it is proprietary and therefore will only play to the full extent on licenced equipment. You will be buying music that won't play to its fullest extent on any device. Why buy into such a restriction?

- it is lossy. You can buy the lossless version, so why bother?

- it was invented to address the issue of streaming large data files. Given that most homes now stream movies with multiple 24 bit channels, the restriction it was intended to address is no longer there

- artists, recording studios, playback device manufacturers,labels and distributors all have to pay a licence to use the system. This is adding additional costs into the industry yet there seems to be no benefit in doing so. Music costs will increase for no listener benefit. More expensive music encourages more piracy, it does not address piracy.

- a little light comes on to prove you are listening to MQA which is supposed to be an indicator of quality. However, there has been debate in the industry about the authenticity of some of the souce material and the accuracy of the information about the equipment used to create the master. This is important in a system that claims to correct for errors in the original recording equipment.

- an authenticity system also allows for the authenticity to be re-interpreted in the future to restrict access to content paid for but not continuously licenced. Think about the impications of a change to licencing terms in the future.

All of this is far more important that 'does it sound any good?'

the real and unique interest of mqa is streaming music from tidal with a dac mqa capable. It is a real benefit from streaming 16/44 flac , with tidal for the moment. It is a major evolution, just a beginning, but a big step. Perhaps, in the future, we will not be obliged to buy hirez audio downloads but just stream directly from tidal, qobuz or another service, perhaps even dsd files.

I find this a real technical step, much more than all the buzz on roon, which is more a facebook disguised interface...Tell me what are you listening at, i will send you some offers.

Keler Pierre posted:

yes, with fully mqa dac. I was not commenting specifically your comment , more some other responses...

I assume that wasn't targeted at my comments either as I've only compared:
MQA to 16/44.1 LPCM both with 16/44.1 LPCM decoders
MQA with MQA decoder to 24/192 LPCM with 24/192 LPCM decoder

N.B. I've not compared MQA with MQA decoder to 16/44.1 LPCM with 16/44.1 LPCM decoder.

Some of us, like me. have no interest in online streaming, paying a subscription to hear music and with all the risks of breakup due to internet problems or, worse, loss of service for any reason, instead wanting the music we like in a store at home, accessible at will and indefinitely. For that, with the low cost of disk storage space, MQA offers no benefit at all. I can quite happily sample new music to see if I like it at any resolution, so SPotify, uTube, artists' samples etc are quite adequate (and free!).

And for those who do use online streaming, unless MQA gives perfect reinstatement of all the detail with no artefacts, wouldn't it be better to stream the full hi res version.

As for needing aN MQA DAC for full decoding, that restricts the choice to those DAC manufacturers that licence the process from Meridien, which is limiting unless they includes the best DACs 

Innocent Bystander posted:

Some of us, like me. have no interest in online streaming, paying a subscription to hear music and with all the risks of breakup due to internet problems or, worse, loss of service for any reason, instead wanting the music we like in a store at home, accessible at will and indefinitely. For that, with the low cost of disk storage space, MQA offers no benefit at all. I can quite happily sample new music to see if I like it at any resolution, so SPotify, uTube, artists' samples etc are quite adequate (and free!).

And for those who do use online streaming, unless MQA gives perfect reinstatement of all the detail with no artefacts, wouldn't it be better to stream the full hi res version.

As for needing aN MQA DAC for full decoding, that restricts the choice to those DAC manufacturers that licence the process from Meridien, which is limiting unless they includes the best DACs 

more and more dacs offer mqa decoding today.  For now, like you, i prefer streaming my own music home ( on my serve), because with my nds it is a better sound quality for now. But in the future, if we will be able to stream full hirez on tidal or other stream service, perhaps i will not continue to use nas, serve ...and buy and download music:     streaming directly, looseless, without any compression, limitless, seems tempting.  I am sure it will be in next future.

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